JP2003117367A - Gas mixer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact gas mixer for mixing a high concentration gas with air to the diluted into low concentration and limiting the variation of the concentration to be small. SOLUTION: The gas mixer is constituted so as to have a blower discharge pipe which is connected to a blower and in which air is sent from the blower, a gas supply pipe mounted to insert the gas discharge opening toward the upstream side of the air flow in the blower discharge pipe and for sending a gas to the blower discharge pipe from the gas discharge opening, an elbow connected to the blow discharge pipe at the downstream side of the gas supply pipe and a straight pipe part connected to the downstream side of the elbow. The mixing is accelerated by sending the gas to be opposite to the flow of the air and generating stripping at the inner edge part of the bend of the elbow to produce a reverse flow zone. Then, a small quantity of the high concentration gas is mixed with a large quantity of air to be diluted so that the variation of the gas concentration is made very small, for example <=1% and the length of the straight pipe part is decreased to be equal to or below the half length of the conventional one to reduce the cost.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to air, other gases,
For example, it relates to a gas mixer for mixing ammonia gas at a low concentration.

[0002]

2. Description of the Related Art Referring to FIG. 8, as an example of a conventional gas mixer for mixing another gas with a low concentration, air and ammonia gas supplied to a denitration device for removing nitrogen oxides from boiler exhaust gas 3 is a system diagram of a gas mixer that mixes ammonia with air at a low concentration to obtain the mixed gas of FIG.

In FIG. 8, a blower outlet pipe 2 is connected to the blower 1 so that air is blown from the blower 1, and in the middle of the blower outlet pipe 2, an ammonia gas supply pipe 3 has its outlet opening 31 through the blower outlet pipe. It is inserted and installed toward the upstream of 2. An ammonia gas supply device (not shown) is connected to the upstream side of the ammonia gas supply pipe 3.

About 20 pipe diameters D are provided downstream of the position where the ammonia gas supply pipe 3 of the blower outlet pipe 2 is installed.
A straight pipe part 4 having a double length L (L = about 20 D) is connected, and the straight pipe part 4 is divided and connected to a plurality of ammonia gas injection nozzles 6 in a duct 5 of the denitration device.

In the conventional gas mixer 10 composed of the ammonia gas supply pipe 3 and the straight pipe portion 4 as described above,
The air a blown from the blower 1 passes through the blower outlet pipe 2 and from the ammonia gas supply pipe 3 installed in the blower outlet pipe 2 into the blower outlet pipe 2 in the direction opposite to the air flow direction with 100% concentration. Ammonia gas b is fed in, and 100% concentration ammonia gas b is mixed with air a in the straight pipe portion 4 to be diluted to become low concentration ammonia mixed gas c, which is a duct 5 of the denitration device connected to the downstream side. It is distributed and supplied to the ammonia gas injection nozzle 6 inside and is ejected into the exhaust gas g flowing in the duct 5.

[0006]

However, the conventional gas mixer 10 described above has the following problems. That is,
In the denitration device, in order to remove the nitrogen oxides in the exhaust gas g in the catalyst layer, the air a fed from the blower 1
Ammonia gas b with a concentration of 00% is diluted to a low concentration so that the dispersion of the ammonia concentration of the ammonia mixed gas c is kept within 1%, and it is distributed to the ammonia injection nozzle 6 in the duct 5 of the denitration device and supplied into the exhaust gas g. There is a need to. 10
The 0% concentration of ammonia gas b is diluted with air a to a low concentration, and it is necessary to increase the length of the straight pipe portion 4 in order to keep the variation in the ammonia concentration within 1%. If the length is too long, there will be disadvantages such as higher pipe manufacturing costs and restrictions on the space for arranging the pipes.

The present invention can mix and dilute the ammonia gas b into the air a to a low concentration and has a mixing performance such that the dispersion of the ammonia concentration is small, for example, within about 1%, and the piping space is compact. It is an object to provide a container.

[0008]

Means for Solving the Problems (1) The present invention has been made to solve the above problems, and as a first means thereof, is connected to a blower and air is blown from the blower. A blower outlet pipe, a gas outlet opening is installed in the blower outlet pipe toward the upstream side of the air flow, and a gas supply pipe for feeding gas from the gas outlet opening into the blower outlet pipe, There is provided a gas mixer characterized by having an elbow connected to a blower outlet pipe at a downstream side of a position of the gas supply pipe and a straight pipe portion connected to a downstream side of the elbow.

According to the gas mixer of the first means having the above structure, when the gas is introduced from the gas supply pipe in the direction opposite to the air flow, the gas does not follow the air flow and is mixed. Although it is promoted and easily diluted, the flow of air causes separation at the inner edge of the bend of the elbow, creating a backflow region,
When the air is disturbed, mixing of the gas is promoted, and even a short straight pipe portion is likely to be diluted, and a large amount of air and a small amount of a high concentration gas have a small concentration variation, for example, within 1%. Can be mixed and diluted to a low concentration.

(2) As a second means, in the gas mixer of the first means, a twist plate formed by twisting around the central axis of the straight pipe portion is attached inside the inlet portion of the straight pipe portion. A gas mixer is provided.

According to the gas mixer of the second means, in addition to the function of the gas mixer of the first means, air and gas flow along the twist plate to generate a swirling flow to promote mixing and dilution, The gas is sufficiently diluted in a short straight pipe portion, and a large amount of air and a small amount of high-concentration gas can be mixed and diluted to a low concentration with a minute variation in concentration, for example, within 1%.

(3) As a third means, there is provided a gas mixer according to the first means, characterized in that an orifice is provided inside the inlet portion of the straight pipe portion.

According to the gas mixer of the third means, in addition to the function of the gas mixer of the first means, by installing an orifice at the inlet of the straight pipe portion, the flow is once stopped by the restriction of the orifice. It promotes the mixing and dilution of the gas, making it easier for the gas to be diluted even in a short straight pipe section, and mixing and diluting a large amount of air and a small amount of a high concentration gas to a low concentration by keeping the variation in concentration to a minute, for example, within 1%. it can.

(4) As a fourth means, in the gas mixer of the third means, a collision plate is provided in the blower outlet pipe so as to face the gas outlet opening. Provide a gas mixer.

According to the gas mixer of the fourth means, in addition to the function of the gas mixer of the third means, the air from the blower collides with a collision plate in the middle of the blower outlet pipe and spreads to the outer periphery of the collision plate. The separated air is separated and disturbed by the collision plate, and the gas introduced from the gas supply pipe spreads to the outer periphery of the collision plate due to the collision with the collision plate, and is easily diluted by the disturbed air flow. It is possible to mix and dilute a high-concentration gas into a low-concentration while keeping the variation in the concentration very small, for example, within 1%.

(5) As a fifth means, a blower outlet pipe connected to the blower and into which air is sent from the blower, an elbow connected to the downstream side of the blower outlet pipe, and a direct connection to the downstream side of the elbow. A pipe part, which is installed so that a gas outlet opening opens immediately after the inner edge of the bend of the elbow, and has a gas supply pipe for feeding gas into the elbow from the gas outlet opening. A gas mixer is provided.

According to the gas mixer of the fifth means, the air blown from the blower is separated at the inner edge of the bend of the elbow, a backflow region is generated in a relatively wide range, and the gas injected into the backflow region is It gradually mixes with air while convection in the reverse flow area, and is further diluted in the straight pipe section, so a large amount of air and a small amount of high concentration gas can be contained in a small concentration variation, for example, within 1%, to achieve low concentration. Can be mixed and diluted.

(6) As a sixth means, a blower outlet pipe connected to the blower and into which air is sent from the blower, an elbow connected to the downstream side of the blower outlet pipe, and a direct connection to the downstream side of the elbow. The pipe part, the diffuser formed inside the inlet part of the straight pipe part, the ring header provided on the outer periphery of the throttle part of the diffuser, the gas supply pipe installed in communication with the ring header, and the ring header There is provided a gas mixer characterized by comprising a plurality of nozzles projecting toward the center of a narrowed portion and feeding gas supplied from the gas supply pipe into the narrowed portion.

According to the gas mixer of the sixth means, the air fed from the blower is contracted by the throttle of the diffuser, and the gas supplied to the ring header through the gas supply pipe is throttled by the nozzle. It is sent near the center of the air and mixes with a contracted flow of air, which makes it easy to dilute it. With a short straight pipe part, a large amount of air and a small amount of high-concentration gas can be stored with a slight variation in concentration, for example, within 1%. Can be mixed and diluted to a low concentration.

(7) As a seventh means, a blower outlet pipe connected to the blower and into which air is introduced, an elbow connected to the downstream side of the blower outlet pipe, and a direct connection to the downstream side of the elbow. On the downstream side of the pipe part and the elbow, the gas outlet opening is installed so as to extend in the straight pipe part toward the downstream direction of the air flow, and the gas outlet opening is opened toward the downstream direction of the air flow. A gas mixer characterized by having a gas supply pipe for feeding gas into the straight pipe portion from the gas outlet opening, and a spiral fin attached to the outer periphery of the gas supply pipe. .

According to the gas mixer of the seventh means, the air sent from the blower flows along the spiral fins on the outer circumference of the gas supply pipe and is sent from the gas supply pipe into the generated swirling flow. The introduced gas is likely to be mixed and diluted with air, and a large amount of air and a small amount of high-concentration gas can be mixed and diluted to a low concentration with a small concentration variation, for example, within 1%, in a short straight pipe portion.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION A gas mixer according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a system diagram of a gas mixer 11 of this embodiment. In FIG.
The same parts as those of the conventional example are designated by the same reference numerals, the description thereof will be omitted, and different parts will be mainly described.

As shown in FIG. 1, a blower outlet pipe 2 is connected to the blower 1 so that air a is fed from the blower 1,
An ammonia gas supply pipe 3 is installed in the middle of the blower outlet pipe 2 in a direction opposite to the flow of the air a, with its outlet opening 31 inserted toward the upstream side of the blower outlet pipe 2.

An ammonia gas supply device (not shown) is connected to the upstream side of the ammonia gas supply pipe 3, but this point is the same in other embodiments to be described later, and repeated description will be omitted. .

An elbow 7 is connected to the blower outlet pipe 2 on the downstream side of the position where the ammonia gas supply pipe 3 is installed,
The straight pipe portion 4 is connected to the downstream side of the elbow 7.

In the gas mixer 11 of the present embodiment, which is composed of the ammonia gas supply pipe 3, the elbow 7 and the straight pipe portion 4 as described above, the flow direction of the air a is reversed in the blower outlet pipe 2. When the ammonia gas b having a concentration of 100% is fed in the direction opposite to the flow of the air a from the ammonia gas supply pipe 3 installed with the outlet opening 31 facing, the flow of the air a is not followed and the mixing is promoted and the dilution is performed. However, in the present embodiment, the flow of the air a further causes separation at the inner edge of the bend of the elbow 7 and the backflow region 8 is generated. This elbow 7
When the air a is disturbed by the backflow region 8 inside,
Mixing of the 0% concentration ammonia gas b is promoted, and even the short straight pipe portion 4 is easily diluted.

Therefore, by supplying 100% -concentration ammonia gas b in the direction opposite to the flow of the air a, and further installing the elbow 7 on the downstream side, a large amount of air a and a small amount of air a can be obtained in the short straight pipe section 4. A 100% concentration of ammonia gas b can be mixed and diluted to a low concentration with a slight variation in the ammonia concentration, for example, within 1%, and the straight pipe portion 4 can be reduced to less than half of the conventional cost, and the cost can be reduced.

A gas mixer according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2A is a system diagram of the gas mixer 12 according to the present embodiment, and FIG. 2B is an enlarged cross-sectional view of a portion A in FIG. In FIG. 2, the same parts as those in the conventional example and the above-described embodiment are designated by the same reference numerals, the description thereof will be omitted, and different parts will be mainly described. Note that this is the same in the description of other embodiments described later.

As shown in FIG. 2, a blower outlet pipe 2 is connected to the blower 1 to blow air a therein, and an ammonia gas supply pipe 3 is provided in the middle of the blower outlet pipe 2 in a direction opposite to the flow of the air a. Is installed by inserting the outlet opening 31 toward the upstream side of the blower outlet pipe 2.

An elbow 7 is connected to the downstream side of the position of the ammonia gas supply pipe 3, and on the downstream side of the elbow 7, a plate is provided inside the inlet portion of the straight pipe portion 4 around the central axis of the straight pipe portion 4. 180
° A twist plate 26 is attached.

In the gas mixer 12 of the present embodiment which is composed of the ammonia gas supply pipe 3, the elbow 7, the twist plate 26 and the straight pipe portion 4 as described above, the flow of the air a in the blower outlet pipe 2 When the ammonia gas b of 100% concentration is sent in the opposite direction to the flow of the air a from the ammonia gas supply pipe 3 installed in the opposite direction, the flow of the air a is not followed and the mixing is promoted and the dilution is likely to occur. In addition, mixing of the air a in the backflow region of the elbow 7 is performed in the same manner as described in the first embodiment, but in the present embodiment, it is further added to the inlet of the straight pipe portion 4 about 180 ° around the pipe central axis. By installing the twisted twisted plate 26, the air a and the ammonia gas b flow along the twisted plate 26, a swirl flow is generated to promote mixed dilution, and the ammonia gas b is sufficiently diluted in the short straight pipe section 4. It

The twist angle of the twist plate 26 is 180.
The angle is not limited to 50 °, but may be appropriately set, but is preferably about 180 ° from the viewpoint of balance between pressure loss and mixed dilution performance.

Therefore, by supplying 100% -concentration ammonia gas b in the direction opposite to the flow of the air a, providing the elbow 7, and further installing a 180 ° twist plate at the inlet of the straight pipe section 4 downstream of the elbow 7. In the short straight pipe part 4, a large amount of air a and a very small amount of 100% concentration ammonia gas b can be mixed and diluted to a low concentration by keeping the dispersion of the ammonia concentration small, for example, within 1%. The cost can be reduced by less than half.

A gas mixer according to a third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a system diagram of the gas mixer 13 of this embodiment.

As shown in FIG. 3, a blower 1 is connected to a blower outlet pipe 2 to blow air a therein, and an ammonia gas supply pipe 3 is provided in the middle of the blower outlet pipe 2 in a direction opposite to the flow of the air a. Is installed by inserting the outlet opening 31 toward the upstream side of the blower outlet pipe 2.

An elbow 7 is connected to the downstream side of the position of the ammonia gas supply pipe 3, and a straight pipe portion 4 is connected to the downstream side of the elbow 7.
Are connected. Then, two orifices 9a and 9b are installed at regular intervals inside the inlet of the straight pipe portion 4 on the downstream side of the elbow 7.

In the gas mixer 13 of the present embodiment, which is composed of the ammonia gas supply pipe 3, the elbow 7, the orifices 9a and 9b, and the straight pipe portion 4 as described above, the air a is provided in the middle of the blower outlet pipe 2. When the ammonia gas b having a concentration of 100% is sent in the opposite direction to the flow of the air a from the ammonia gas supply pipe 3 installed in the opposite direction to the flow, the flow of the air a is not followed and the mixing is promoted and diluted. Although it becomes easier and mixing is promoted also by the backflow region of the air a generated in the elbow 7, in the present embodiment, by further installing the orifices 9a and 9b at the inlet of the straight pipe portion 4, the first stage is provided. By restricting the orifice 9a, the flow is once stopped to promote the mixed dilution of the ammonia gas b, and the second stage orifice 9b also similarly stops the flow to promote the mixed dilution.
The ammonia gas b is likely to be diluted even in the short straight pipe section 4.

The number of orifices may be one, and
The mixing and diluting performance is improved by inserting a plurality of sheets, but the pressure loss in the gas mixer 13 may be increased and the load of the blower 1 or the like may be increased. Therefore, from the balance with the mixing and diluting performance, two orifices are required. preferable.

Therefore, 100% concentration of ammonia gas b is sent in the direction opposite to the flow of the air a, the elbow 7 is installed further downstream, and the inlet 2 of the straight pipe portion 4 on the downstream side is installed.
By installing a plurality of orifices 9a and 9b, a large amount of air a and a small amount of 100% -concentration ammonia gas b can be contained in the short straight pipe portion 4 with a small dispersion of the ammonia concentration, for example, within 1% to obtain a low concentration. It is possible to mix and dilute, and the straight pipe part 4 is less than half of the conventional one, and the cost can be reduced.

A gas mixer according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4A is a system diagram of the gas mixer 14 of the present embodiment, and FIG. 4B is an enlarged sectional view of a B part in FIG. 4A.

As shown in FIG. 4, the blower outlet pipe 2 is connected to the blower 1 to feed the air a, and the ammonia gas supply pipe 3 is provided in the middle of the blower outlet pipe 2 in the direction opposite to the flow of the air a. Is installed by inserting the outlet opening 31 toward the upstream side of the blower outlet pipe 2.

An elbow 7 is connected to the downstream side of the position of the ammonia gas supply pipe 3, and a straight pipe portion 4 is connected to the downstream side of the elbow 7.
Are connected. Then, two orifices 9a and 9b are installed at regular intervals inside the inlet of the straight pipe portion 4 on the downstream side of the elbow 7.

Then, from the above-mentioned outlet opening 31 of the ammonia gas supply pipe 3 to the outlet opening 31 of the ammonia gas supply pipe 3.
A collision plate 21 is installed facing the outlet opening 31 at an upstream side position having a diameter of 1 to 2 times. The collision plate 21 is supported and fixed in the blower outlet pipe 2 by a reinforcing stay 22.

The ammonia gas supply pipe 3, the collision plate 21, the elbow 7, the orifices 9a and 9b and the straight pipe portion 4 as described above.
In the gas mixer 14 of the present embodiment configured as described above, the air a from the blower 1 collides with the collision plate 21 in the middle of the blower outlet pipe 2, and the air a spreading and flowing to the outer periphery of the collision plate 21 collides with the collision plate 21. It peels off and is disturbed. Then, when the ammonia gas b having a 100% concentration is fed from the ammonia gas supply pipe 3 which is installed with the outlet opening 31 directed in the direction opposite to the flow of the air a in the blower outlet pipe 2, the ammonia gas b is converted into the collision plate 21. Is spread to the outer circumference of the collision plate 21 due to the collision with and is easily diluted by the turbulent flow of the air a. Further, the backflow region of the air a generated in the elbow 7 promotes the mixing, and by installing the orifices 9a and 9b at the inlet of the straight pipe portion 4, the flow is temporarily stopped by the restriction of the orifice 9a of the first stage. The mixed dilution of the ammonia gas b is promoted, and the mixed dilution is similarly promoted also in the orifice 9b of the second stage, so that the ammonia gas b is easily diluted even in the short straight pipe portion 4.

Therefore, 100% concentration of ammonia gas b is sent in the opposite direction to the flow of the air a to collide with the collision plate 21, and further the elbow 7 is installed on the downstream side, and the inlet of the straight pipe section 4 on the downstream side. By installing two orifices 9a, 9b in the short straight pipe section 4, a large amount of air a and a small amount of 10
The ammonia gas b of 0% concentration can be mixed and diluted to a low concentration by keeping the dispersion of the ammonia concentration small, for example, within 1%, and the straight pipe portion 4 can be reduced to half or less of the conventional cost, and the cost can be reduced.

A gas mixer according to a fifth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a system diagram of the gas mixer 15 of the present embodiment.

As shown in FIG. 5, the blower 1 is connected to the blower outlet pipe 2 so that the air a is fed from the blower 1.
An elbow 7 is connected to the downstream side of the blower outlet pipe 2, and an ammonia gas supply pipe 3a is installed so that an outlet opening 31a for feeding the ammonia gas b is opened inside the elbow 7 immediately after the bend. . The straight pipe portion 4 is connected to the downstream side of the elbow 7.

In the gas mixer 15 of the present embodiment which is composed of the elbow 7, the ammonia gas supply pipe 3a and the straight pipe portion 4 as described above, the air a fed from the blower 1 is the blower outlet pipe 2 The elbow 7 connected to the inner side of the elbow 7 is separated immediately after the bend, and a backflow region 8 is generated in a relatively wide range. Ammonia gas b of 100% concentration fed into the elbow from the ammonia gas supply pipe 3a installed so that the outlet opening 31a opens immediately after the inner edge of the bend of the elbow 7.
Is fed into the reverse flow region 8 and, as a result, ammonia gas b
Is gradually mixed with air a while convection in the reverse flow region 8 and further diluted in the straight pipe portion 4.

Therefore, by providing the outlet opening 31a of the ammonia gas supply pipe 3a immediately after the inner edge of the bend in the elbow 7 and feeding the ammonia gas b having a 100% concentration, a large amount of air can be supplied to the short straight pipe portion 4. A and a small amount of 100% concentration of ammonia gas b can be mixed and diluted to a low concentration by keeping the dispersion of the ammonia concentration in a minute amount, for example, within 1%, and the straight pipe section 4 can be reduced to less than half of the conventional cost to reduce the cost. be able to.

A gas mixer according to a sixth embodiment of the present invention will be described with reference to FIG. FIG. 6A is a system diagram of the gas mixer 16 of the present embodiment, and FIG.
(A) It is the CC sectional view taken on the line in the arrow.

As shown in FIG. 6, a blower outlet pipe 2 is connected to the blower 1 so that the air a is fed from the blower 1,
An elbow 7 is connected to the downstream side of the blower outlet pipe 2, and the diffuser 23 is provided inside the straight pipe portion 4 immediately after the elbow 7.
Is installed, the throttle part of the diffuser 23 (the minimum area part)
A ring header 24 for supplying ammonia gas is provided on the outer periphery of 23a, and the ammonia gas supply pipe 3b is connected to the ring header 24.

Ring header 24 for supplying ammonia gas
Is about 7 of the inner radius R of the throttle portion 23a of the diffuser 23.
The nozzle 25 having a length of 0% (0.7R) has a narrowed portion 23a.
A plurality of them are provided so as to project toward the center of, and are arranged in the circumferential direction, and the ammonia gas b from the ammonia gas supply pipe 3b is ejected from the nozzle 25 toward the center of the throttle portion 23a.

Elbow 7, diffuser 2 as described above
3, the ring header 24, the nozzle 25, the ammonia gas supply pipe 3b and the straight pipe portion 4 in the gas mixer 16 of the present embodiment, the air a sent from the blower 1
The diffuser 23 at the inlet of the straight pipe portion 4 immediately after the elbow 7 reduces the flow of the air a at the throttle portion 23a. At this time, the 100% -concentration ammonia gas b is supplied to the ring header 24 via the ammonia gas supply pipe 3b. Ammonia gas b is further drawn from the nozzle 25 provided in the ring header 24 to the center of the narrowed portion 23a.
It is introduced at a position that is about 70% closer to the inner radius R of a, mixes with the contracted flow of air a, and is easily diluted.

Therefore, the diffuser 23 is provided inside the inlet portion of the straight pipe portion 4 downstream of the elbow 7 and the throttle portion 23a thereof is provided.
A ring header 24 for supplying ammonia gas is provided on the outer periphery of the nozzle 2 so that the ammonia gas b having a concentration of 100% reaches the center of the throttle portion 23a.
5, the ammonia gas b and the narrowed portion 23a are provided.
The mixing of the air a with the contracted flow of the air a is promoted, and a large amount of air a and a small amount of 100% concentration of the ammonia gas b are contained in the short straight pipe portion 4 with a small variation in the ammonia concentration, for example, within 1% to reduce the variation. It can be mixed and diluted to a concentration, and the straight pipe part 4 can be less than half of the conventional one, and the cost can be reduced.

A gas mixer according to a seventh embodiment of the present invention will be described with reference to FIG. FIG. 7A is a system diagram of the gas mixer 17 of the present embodiment, and FIG. 7B is an enlarged cross-sectional view of the E portion in FIG. 7A.

As shown in FIG. 7, a blower outlet pipe 2 is connected to the blower 1 so that air a is fed from the blower 1,
An elbow 7 is connected to the downstream side of the blower outlet pipe 2, and a straight pipe section 4 is connected to the downstream side of the elbow 7. Elbow 7
The elbow 7 and the straight pipe portion 4 are provided on the downstream side of the bent portion of
The ammonia gas supply pipe 3c is inserted so as to extend into the straight pipe portion 4 toward the downstream direction of the air a therein, and an outlet opening 31c for feeding the ammonia gas b of the ammonia gas supply pipe 3c into the air a. Is open toward the downstream side of the air a. A spiral fin 27 is provided on the outer peripheral surface of the ammonia gas supply pipe 3c.

In the gas mixer 17 of the present embodiment which is composed of the elbow 7, the ammonia gas supply pipe 3c, the fins 27 and the straight pipe portion 4 as described above, the air a fed from the blower 1 is Flowing from the downstream side of the elbow 7 to the upstream side of the straight pipe portion 4 along the fins 27 of the ammonia gas supply pipe 3c, a swirl flow 27a is generated on the upstream side in the straight pipe portion 4.
In the swirling flow 27a of the air a, the ammonia gas supply pipe 3
When the 100% -concentration ammonia gas b is fed from the outlet opening 31c of c, the ammonia gas b is easily mixed and diluted with the air a, and is further diluted by the straight pipe portion 4.

Therefore, by attaching the spiral fin 27 to the ammonia gas supply pipe 3c which is inserted and installed on the downstream side of the elbow 7, the air
Swirl flow 27a is generated, and 100% is generated in the swirl flow 27a.
By feeding the ammonia gas b having a concentration, the mixed dilution of the ammonia gas b and the air a is promoted, and a large amount of the air a and a very small amount of the ammonia gas b having a concentration of 100% are generated in the short straight pipe portion 4.
Can be mixed and diluted to a low concentration by keeping the dispersion of the ammonia concentration minute, for example, within 1%, and the straight pipe portion 4 can be reduced to less than half that of the conventional case and the cost can be reduced.

The embodiment of the present invention has been described above.
Needless to say, the present invention is not limited to the above-described embodiment, and various modifications may be made to the specific structure within the scope of the present invention.

In particular, both the above-mentioned conventional example and the embodiment have been described by taking a gas mixer for mixing 100% concentration of ammonia gas with air at a low concentration as an example, but the present invention is not limited to ammonia. It is generally applied to a gas mixer for mixing a predetermined gas with air at a low concentration.

[0061]

(1) According to the invention of claim 1, the gas mixer is provided with a blower outlet pipe connected to the blower and into which air is fed, and a gas outlet opening in the blower outlet pipe. A gas supply pipe that is installed by being inserted toward the upstream side of the air flow and that feeds gas from the gas outlet opening into the blower outlet pipe, and is connected to the blower outlet pipe downstream from the position of the gas supply pipe. Since it is configured to have an elbow and a straight pipe part connected to the downstream side of the elbow,
When the gas is introduced from the gas supply pipe in the direction opposite to the air flow, the gas does not follow the air flow, promoting mixing and facilitating dilution, but in addition, the air flow causes the elbow to bend at the inner edge. Separation causes a backflow region and disturbs the air, which promotes gas mixing and facilitates dilution even in a short straight pipe section, resulting in a large amount of air and a small amount of highly concentrated gas with uneven concentration. A small amount, for example, within 1%, can be mixed and diluted to a low concentration, and the straight pipe portion can be reduced to less than half of the conventional one, and the cost can be reduced.

(2) According to the invention of claim 2, claim 1
The gas mixer according to claim 1, wherein a twist plate formed by twisting around the central axis of the straight pipe portion is attached inside the inlet portion of the straight pipe portion, and thus the effect of the invention of claim 1 In addition, air and gas flow along the twist plate, swirling flow is generated to promote mixing and dilution, the gas is sufficiently diluted in the short straight pipe part, and a large amount of air and a small amount of high concentration gas are dispersed in concentration. Can be mixed and diluted to a low concentration by containing it in a minute amount, for example, within 1%, and the straight pipe part can be reduced to less than half of the conventional cost, and the cost can be reduced.

(3) According to the invention of claim 3, claim 1
In the gas mixer according to claim 1, since the orifice is provided inside the inlet portion of the straight pipe portion, in addition to the effect of the invention of claim 1, the orifice is installed at the inlet portion of the straight pipe portion. The flow is once stopped by the restriction of the orifice, which promotes the mixing and dilution of the gas, making it easier for the gas to be diluted even in a short straight pipe portion, and to make a large amount of air and a small amount of highly concentrated gas have a small concentration variation, for example, 1%. It can be mixed and diluted to a low concentration by containing it in less than half, and the straight pipe part can be reduced to less than half that of conventional products and cost can be reduced. (4) According to the invention of claim 4, in the gas mixer according to claim 3, a collision plate is installed in the blower outlet pipe so as to face the gas outlet opening. Therefore, in addition to the effect of the invention of claim 3, the air from the blower collides with the collision plate in the middle of the blower outlet pipe, and the air that has spread to the outer periphery of the collision plate is separated and disturbed by the collision plate,
The gas sent from the gas supply pipe spreads to the outer periphery of the collision plate due to the collision with the collision plate, and is easily diluted by the disturbed air flow, and a large amount of air and a small amount of highly concentrated gas have a small concentration variation. For example, it can be mixed and diluted to a low concentration by containing it within 1%, and the straight pipe part can be less than half of the conventional one, and the cost can be reduced.

(5) According to the invention of claim 5, the gas supply pipe is connected to the blower, the blower outlet pipe to which air is fed from the blower, the elbow connected to the downstream side of the blower outlet pipe, and the same. A straight pipe part connected to the downstream side of the elbow, a gas outlet opening is installed immediately after the inner edge of the bend of the elbow, and a gas supply pipe for introducing gas into the elbow from the gas outlet opening is provided. I configured it to have,
The air blown from the blower separates at the inner edge of the bend in the elbow, and a backflow region occurs in a relatively wide range.The gas injected into the backflow region gradually convects in the backflow region and gradually mixes with the air. Since it is diluted in the straight pipe section, a large amount of air and a small amount of high-concentration gas can be used, for example, with a small concentration variation, for example, 1%.
It can be mixed and diluted to a low concentration by containing it in less than half, and the straight pipe part can be reduced to less than half that of conventional products and cost can be reduced.

(6) According to the invention of claim 6, the gas supply pipe is connected to a blower, and a blower outlet pipe is connected to the blower for feeding air, and an elbow connected to the downstream side of the blower outlet pipe. A straight pipe part connected to the downstream side of the elbow, a diffuser formed inside the inlet part of the straight pipe part, a ring header provided on the outer periphery of the throttle part of the diffuser, and a gas installed in communication with the ring header Since the supply pipe and the ring header are provided with a plurality of nozzles projecting toward the center of the throttle portion and for feeding the gas supplied from the gas supply pipe into the throttle portion, The air sent in is contracted by the diffuser at the throttle part, and the gas supplied to the ring header via the gas supply pipe is sent from the nozzle near the center of the throttle part and mixed with the contracted flow of air,
It becomes easy to dilute, and it is possible to mix and dilute a large amount of air and a small amount of high-concentration gas in a short straight pipe part with a small concentration variation, for example within 1% to a low concentration, and the straight pipe part is less than half of the conventional Therefore, the cost can be reduced.

(7) According to the invention of claim 7, the gas supply pipe is connected to the blower, the blower outlet pipe to which air is fed from the blower, the elbow connected to the downstream side of the blower outlet pipe, The straight pipe portion connected to the downstream side of the elbow, the gas outlet opening is installed so as to extend in the straight pipe portion toward the downstream direction of the air flow on the downstream side in the elbow A gas supply pipe that opens in the downstream direction of the flow and that feeds gas into the straight pipe portion from the gas outlet opening, and a spiral fin attached to the outer circumference of the gas supply pipe Therefore, the air sent from the blower flows along the spiral fins on the outer circumference of the gas supply pipe, and the gas sent from the gas supply pipe is easily mixed and diluted with air during the generated swirling flow. , Short straight pipe section with a large amount of air and trace amount The high concentration of gas in small variations in concentration, for example, can be mixed and diluted to a low concentration contained within 1%,
Since the straight pipe section is less than half that of the conventional type, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a system diagram of a gas mixer according to a first embodiment of the present invention.

FIG. 2 (a) is a system diagram of a gas mixer according to a second embodiment of the present invention, and FIG. 2 (b) is an enlarged cross-sectional view of a portion A in (a).

FIG. 3 is a system diagram of a gas mixer according to a third embodiment of the present invention.

FIG. 4 (a) is a system diagram of a gas mixer according to a fourth embodiment of the present invention, and FIG. 4 (b) is an enlarged cross-sectional view of portion B in (a).

FIG. 5 is a system diagram of a gas mixer according to a fifth embodiment of the present invention.

FIG. 6 (a) is a system diagram of a gas mixer according to a sixth embodiment of the present invention, and FIG. 6 (b) is a sectional view taken along line CC in FIG. 6 (a).

FIG. 7 (a) is a system diagram of a gas mixer according to a seventh embodiment of the present invention, and FIG. 7 (b) is an enlarged cross-sectional view of an E section in (a).

FIG. 8 is a system diagram of a conventional gas mixer.

[Explanation of symbols]

1 Blower 2 Blower outlet pipe 3, 3a, 3b, 3c Ammonia gas supply pipe 4 Straight pipe portion 5 Duct 6 Ammonia gas injection nozzle 7 Elbow 8 Backflow portion 9a, 9b Orifice 11, 12, 13, 14, 15, 16, 17 Gas mixer 21 Collision plate 22 Reinforcing stay 23 Diffuser 23a Throttle portion 24 Ring header 25 Nozzle 26 Twist plate 26a Swirling flow 27 Fin 27a Swirling flow 31, 31a, 31c Exit opening

Continued front page    (72) Inventor Masaaki Taniguchi             5-717-1, Fukahori-cho, Nagasaki-shi Mitsubishi Heavy Industries             Business Nagasaki Institute (72) Inventor Shinya Urata             5-717-1, Fukahori-cho, Nagasaki-shi Mitsubishi Heavy Industries             Business Nagasaki Institute F-term (reference) 4D002 AA12 BA06 CA01 DA07 GA03                       GB20                 4G035 AB02 AC06 AC10 AC12

Claims (7)

[Claims] 1. A blower outlet pipe connected to a blower for feeding air from the blower, and a gas outlet opening is inserted into the blower outlet pipe so as to be directed toward an upstream side of the air flow. It has a gas supply pipe for feeding gas from the opening into the blower outlet pipe, an elbow connected to the blower outlet pipe downstream of the position of the gas supply pipe, and a straight pipe portion connected to the downstream side of the elbow. A gas mixer characterized in that 2. The gas mixer according to claim 1, wherein a twist plate formed by twisting around the central axis of the straight pipe portion is attached inside the inlet portion of the straight pipe portion. Gas mixer. 3. The gas mixer according to claim 1, wherein an orifice is provided inside the inlet of the straight pipe section. 4. The gas mixer according to claim 3, further comprising: a collision plate mounted inside the blower outlet pipe so as to face the gas outlet opening. 5. A blower outlet pipe connected to a blower and receiving air from the blower, an elbow connected to the downstream side of the blower outlet pipe, a straight pipe portion connected to the downstream side of the elbow, and a bend of the elbow. A gas mixer, which is installed so that a gas outlet opening is opened immediately after the inner edge of the gas mixer, and has a gas supply pipe for feeding gas into the elbow from the gas outlet opening. 6. A blower outlet pipe connected to a blower and receiving air from the blower, an elbow connected to the downstream side of the blower outlet pipe, a straight pipe portion connected to the downstream side of the elbow, and a straight pipe portion. Formed inside the inlet of the diffuser, a ring header provided on the outer periphery of the throttle part of the diffuser, a gas supply pipe installed in communication with the ring header, and a protrusion on the ring header toward the center of the throttle part A gas mixer, comprising a plurality of nozzles that are provided and that feed the gas supplied from the gas supply pipe into the narrowed portion. 7. A blower outlet pipe connected to a blower for feeding air from the blower, an elbow connected to the downstream side of the blower outlet pipe, a straight pipe portion connected to the downstream side of the blower, and the inside of the elbow. On the downstream side, the gas outlet opening is installed to be inserted so as to extend in the straight pipe portion toward the downstream direction of the air flow, and the gas outlet opening is opened toward the downstream direction of the air flow and from the gas outlet opening. A gas mixer comprising: a gas supply pipe for feeding gas into a straight pipe portion; and a spiral fin attached to the outer periphery of the gas supply pipe.